Research on Voltage Stability of Photovoltaic PCC Based on the Hopf Bifurcation Theory

Due to the large number of distributed generation and nonlinear components in the Photovoltaic (PV) System, Voltage condition at the point of common coupling (PCC) faces severe challenges. Evaluation of the PCC voltage stability has become critical to the steady operation of the PV system. PV system is a typical nonlinear nonautonomous system, and bifurcation theory, as one the effective ways to solve the nonlinear dynamic system, was adopted to conduct a research on voltage stability or collapse on the PCC. In the paper, a PV system equivalent circuit model was proposed. In order to find the main parameters that contribute most to the voltage instability on the PCC, a mathematical analysis was conducted based on the equivalent circuit. Then, with irradiance intensity chosen as the bifurcation parameter, the Hopf bifurcation simulation was conducted. A MATLAB m-file was developed to study the voltage stability analysis. A MATCONT bifurcation software has been used to conduct the bifurcation analysis.